Sluggish mouse using kdm instead of gdm

In an effort to fix this issue, I removed gdm and replaced it with kdm.

Now when I switch to the session for the other user, the mouse becomes really sluggish and the machine is unusable.

How much RAM do you have?

I’d solved most of my issues by running:

# i'm have 4GB of RAM.
# And feel all right without the swap.
swapoff -a

# possibly.
zramstart

No other ideas.

PS: